"Maya project, the managed service contract we won recently, is to design and plan O2’s future network and we are not managing O2’s current network. However, we are ready to offer support if requested by O2,” said a Huawei spokeswoman.

The network problems raise a real concern for the fast approaching Olympic Games this summer.

Steven Hartley, practice leader at Ovum Telecoms Strategy said: “The huge influx of visitors to London ahead of the games will cause network traffic spikes, putting pressure on the UK's mobile networks, which already have a poor reputation compared to others in Western Europe. While UK mobile operators claim to be prepared, they have not yet given indication of the scale of their plans.”

“Mobile capacity upgrades at key transport and crowd hotspots will undoubtedly take place before the Games. However, if there is a major public transport failure, the spilling over of people from a location where high network traffic has been anticipated to less well-prepared peripheral cells could prove disastrous.”